Improve generate_changelog.py (#17)

* See rerun-io/rerun#7844 for motivation

RELEASES.md

@@ -0,0 +1,9 @@
+# Release Checklist
+
+* [ ] Update `CHANGELOG.md` using `./scripts/generate_changelog.py --version 0.NEW.VERSION`
+* [ ] Bump version numbers in `Cargo.toml` and run `cargo check`.
+* [ ] `git commit -m 'Release 0.x.0 - summary'`
+* [ ] `cargo publish --quiet -p new_project_name`
+* [ ] `git tag -a 0.x.0 -m 'Release 0.x.0 - summary'`
+* [ ] `git pull --tags && git tag -d latest && git tag -a latest -m 'Latest release' && git push --tags origin latest --force && git push origin main ; git push --tags`
+* [ ] Do a GitHub release: https://github.com/rerun-io/new_repo_name/releases/new

scripts/generate_changelog.py

@@ -16,6 +16,7 @@
 import re
 import sys
 from dataclasses import dataclass
+from datetime import date
 from typing import Any, Optional
 
 import requests
@@ -110,13 +111,41 @@ def print_section(crate: str, items: list[str]) -> None:
     print()
 
 
+def commit_range(new_version: str) -> str:
+    parts = new_version.split(".")
+    assert len(parts) == 3, "Expected version to be on the format X.Y.Z"
+    major = int(parts[0])
+    minor = int(parts[1])
+    patch = int(parts[2])
+
+    if 0 < patch:
+        # A patch release.
+        # Include changes since last patch release.
+        # This assumes we've cherry-picked stuff for this release.
+        diff_since_version = f"0.{minor}.{patch - 1}"
+    elif 0 < minor:
+        # A minor release
+        # The diff should span everything since the last minor release.
+        # The script later excludes duplicated automatically, so we don't include stuff that
+        # was part of intervening patch releases.
+        diff_since_version = f"{major}.{minor - 1}.0"
+    else:
+        # A major release
+        # The diff should span everything since the last major release.
+        # The script later excludes duplicated automatically, so we don't include stuff that
+        # was part of intervening minor/patch releases.
+        diff_since_version = f"{major - 1}.{minor}.0"
+
+    return f"{diff_since_version}..HEAD"
+
+
 def main() -> None:
     parser = argparse.ArgumentParser(description="Generate a changelog.")
-    parser.add_argument("--commit-range", help="e.g. 0.1.0..HEAD", required=True)
+    parser.add_argument("--version", required=True, help="The version of the new release, e.g. 0.42.0")
     args = parser.parse_args()
 
     repo = Repo(".")
-    commits = list(repo.iter_commits(args.commit_range))
+    commits = list(repo.iter_commits(commit_range(args.version)))
     commits.reverse()  # Most recent last
     commit_infos = list(map(get_commit_info, commits))
 
@@ -170,6 +199,7 @@ def main() -> None:
         line = line[0].upper() + line[1:]  # Upper-case first letter
         prs[i] = line
 
+    print(f"## {args.version} - {date.today()}")
     print()
     print(f"Full diff at https://github.com/{OWNER}/{REPO}/compare/{args.commit_range}")
     print()

scripts/template_update.py

@@ -68,6 +68,7 @@
     "clippy.toml",
     "Cranky.toml",
     "deny.toml",
+    "RELEASES.md",
     "rust-toolchain",
     "scripts/clippy_wasm/",
     "scripts/clippy_wasm/clippy.toml",